Add invoice comment

Add a comment to an invoice. Set isInternal to true for merchant-only comments.

Related endpoints

• PUT /invoices/external/batch — Batch upsert invoices by external ID
• GET /invoices — List invoices
• POST /invoices — Create invoice
• GET /invoices/{id} — Get invoice
• PATCH /invoices/{id} — Update invoice
• DELETE /invoices/{id} — Delete invoice
• POST /invoices/{id}/refund — Refund invoice
• POST /invoices/{id}/reject — Reject invoice

Idempotency

Pass an Idempotency-Key header (UUID v4 recommended) to make retries safe. Keys are valid for 24 hours; see the idempotency guide.

curl -X POST "https://api.revkeen.com/v2/invoices/00000000-0000-0000-0000-000000000000/comments" \  -H "x-api-key: $REVKEEN_API_KEY" \  -H "Content-Type: application/json" \  -d '{    "content": "Payment reminder sent to customer"  }'

{
  "data": {
    "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",
    "invoiceId": "4f163819-178d-470c-a246-d6768476a6ec",
    "userId": "string",
    "content": "string",
    "isInternal": true,
    "createdAt": "string",
    "updatedAt": "string"
  },
  "requestId": "string"
}